JP2011124399A - Semiconductor sensor and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost semiconductor sensor with stable characteristics which does not need the use of an expensive facility for bonding of substrates, and can bond them at a low temperature securing stable characteristics, wherein the semiconductor sensor is constituted by bonding a substrate having a semiconductor layer with a movable part or a semiconductor substrate with the movable part to a glass substrate. <P>SOLUTION: While a semiconductor layer 13 of an SOI substrate 1 with a movable part 131 and a glass substrate 2, and a semiconductor substrate 11 of the SOI substrate 1 and a glass substrate 3 are aligned and metal layers formed therein respectively are brought into contact with each other, they are integrated forming a bonded part 4a by receiving a pressing force mutually owing to an electrostatic attraction resulting from a DC voltage connected so that the glass substrate side becomes a negative potential. Electrostatic attraction by the DC voltage is generated between the region of the glass substrate without the metal layer, the semiconductor layer and semiconductor substrate opposed thereto, and the metal layer thereon. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technology for reducing the cost and improving the performance of a semiconductor sensor used in automobiles, home appliances, industrial measuring instruments, and the like.

  As an example of an electrostatic capacitance type semiconductor sensor, there is one that has an island structure in which a movable part to be a movable electrode and an electrode pattern are separated by processing a silicon active layer of an SOI substrate until it reaches an insulator layer. In many cases, a sensor having such a movable part has a sealed structure in order to protect the movable part and to use or prevent air damping. In such a sealed structure sensor, it is necessary to take out the electrode from the inside of the sealed structure.

  FIG. 5 is a conceptual cross-sectional view showing the structure of an example of such a conventional semiconductor sensor and the manufacturing method thereof, FIG. 6 shows the structure of the main part, and FIG. Sectional drawing and (b) are sectional drawings of an outer peripheral part. In this conventional example, the SOI substrate 1, the glass substrate 2, and the glass substrate 3 are integrated by metal bonding. FIG. 4 is a block diagram showing the manufacturing process.

  This semiconductor sensor includes an SOI substrate 1 in which a movable part 131 and an electrode pattern 132 are formed on a semiconductor layer 13 which is a silicon active layer, and two glass substrates 2 and 3 which are arranged and integrated on both sides thereof. It consists of and. At least the glass substrate 2 is provided with an electrode (not shown) that faces the movable portion 131.

  The SOI substrate 1 and the glass substrate 2 are integrated by a metal joint portion 4 formed by metal joining the metal layer 14 and the metal layer 23 formed on these substrates. By this metal joining, the movable part 131 which is a vibrating body is electrically connected to the outside simultaneously with the integration. The movable part 131 formed in the central part of the semiconductor layer 13 of the SOI substrate 1 is formed on the surface of the glass substrate 2 and the electrode layer 132 of the semiconductor layer 13 and the metal layer 14 formed on a part of the surface thereof. It is electrically connected to the outside through the metal layer 23 and the through hole metal layer 22 formed on the inner surface of the through hole 21 of the glass substrate 2. Further, the through hole 21 is hermetically sealed by metal bonding of the metal layer 14 and the metal layer 23.

  Similarly, the electrode on the glass substrate side not shown is also connected to the outside through a through hole, and in order to make the inside airtight, the same metal bonding as described above is also adopted in this through hole portion.

The integration of the SOI substrate 1 and the glass substrate 3 is exactly the same.
Metal bonding is performed by positioning and overlapping members to be bonded, and pressurizing while heating to a predetermined temperature. The heating temperature varies depending on the material of the metal layer, but it is around 250 ° C. in the combination of gold and gold.

  In order to integrate the SOI substrate 1 with the glass substrate 2 and the glass substrate 3, in addition to the above-described metal bonding, anodic bonding can also be employed. In this case, the semiconductor layer 13 of the SOI substrate 1 and the glass substrate 2 and the semiconductor substrate 11 of the SOI substrate 1 and the glass substrate 3 can be directly bonded.

  FIGS. 7 to 9 show the case of integration by anodic bonding, FIG. 7 is a conceptual cross-sectional view showing the structure of the semiconductor sensor and its manufacturing method, and FIG. 8 is a through hole 21 immediately after anodic bonding. FIG. 9 is a cross-sectional view showing a state in which a through hole metal layer 22a is formed on the inner surface of the through hole 21. FIG.

  The principle of anodic bonding has been reported in many documents such as Patent Document 1. Briefly, when glass and silicon are brought into contact and a DC voltage is applied while heating the glass side to a negative potential and the silicon side to a positive potential, the cations contained in the glass are moved to the negative electrode side. As a result of drifting, a depletion layer of cations is generated on the interface side with silicon. An electrostatic attractive force is generated between the negative charge of the cation-deficient layer and the positive charge sent to the interface side of silicon, and the electrostatic attractive force causes the glass and silicon to be pressed against each other and bonded. In the case of such anodic bonding, it is necessary to heat the member to be bonded to about 400 ° C.

  Normally, in the state of anodic bonding, as shown in FIG. 8, the internal electrode pattern 132 and the like are not connected to the outside, so that the internal electrode pattern 132 and the like are electrically connected to the outside. After bonding, a through hole metal layer 22a is formed in the through hole 21 of the glass substrate 2.

  As a bonding method for lowering the bonding temperature of this anodic bonding, there is one disclosed in Patent Document 2. In this method, a multilayer metal film is formed on the silicon side, and the metal film and glass are bonded by anodic bonding. The multilayer metal film has at least a soft metal layer and an active metal layer to be firmly bonded to glass at a low temperature, and an intermediate metal for preventing diffusion and reaction between the two layers as necessary. The layer is interposed.

Japanese Patent Laid-Open No. 10-259039 JP 2004-262698 A

  In the case of integration by metal bonding as described in the background art section, it is necessary to position and pressurize the bonding surfaces of the members to be bonded, and there is a facility equipped with a pressure mechanism and an alignment mechanism. Necessary. Therefore, it is difficult to obtain alignment accuracy with heating, it is difficult to press the surface uniformly due to the effects of substrate warpage and thickness unevenness, etc., and in-plane bonding tends to be non-uniform, and the yield rate of bonded products decreases. It is difficult to reduce the cost because it is easy and the pressurization mechanism requires high-precision control (load, alignment, pressurization direction, etc.), making it an expensive facility.

  In addition, when the semiconductor and the glass are directly bonded by anodic bonding, as described above, it is necessary to increase the member temperature at the time of bonding to about 400 ° C., and due to the difference in coefficient of linear expansion between the members, Stress is generated between the two members at room temperature, and even a slight difference affects the structure and device characteristics. For reducing the member temperature at the time of anodic bonding, as disclosed in Patent Document 2, the active metal film for firmly bonding to glass at a temperature lower than 400 ° C. and adhesion are improved. There is one in which an intermediate metal film for preventing a reaction between a soft metal film and both films is formed on the semiconductor side. In this case, equipment for forming three types of metal films having different functions is required.

  The object of the present invention is a structure different from that disclosed in Patent Document 2, which solves both the above-mentioned problem that cost reduction is difficult and the problem that the temperature at the time of joining becomes high, and the cost is low. Another object of the present invention is to provide a semiconductor sensor that can obtain stable characteristics at a low substrate bonding temperature.

A feature of the present invention is that a bonding material for metal bonding and a pressing force generation mechanism for anodic bonding are combined to bond a glass substrate and a semiconductor layer or a semiconductor substrate.
The invention of claim 1 is a semiconductor sensor comprising a substrate having a semiconductor layer on at least one surface and having a movable part formed on the semiconductor layer, and a glass substrate, wherein the both The substrate is bonded by the metal layer formed on each of the semiconductor layer and the glass substrate, and the area of the metal layer for bonding formed on the glass substrate corresponds to the thickness of the bonded metal layer. Is smaller than the area of the glass substrate region facing the semiconductor layer.

  By selecting the material of the metal layer formed on each of the semiconductor layer and the glass substrate, the temperature for bonding can be lowered to around 200 ° C. Further, the area of the metal layer for bonding formed on the glass substrate is made smaller than the area of the glass substrate region facing the semiconductor layer by a distance corresponding to the thickness of the bonding metal layer. A region where the metal layer is not formed can exist in a region of the glass substrate facing the semiconductor layer at a distance corresponding to the thickness of the metal layer. Since this region (of the glass substrate on which the metal layer is not formed) is the portion where the semiconductor layer and the metal layer on the semiconductor layer and the glass substrate directly face each other closest to each other, the semiconductor layer or the metal on the semiconductor layer As a result, it becomes possible to bond the metal layers that are in contact with each other with an applied voltage that is used for ordinary anodic bonding. .

  The invention of claim 2 is a semiconductor sensor configured by bonding a semiconductor substrate on which a movable part is formed and a glass substrate, wherein the both substrates are bonded by a metal layer formed on each, and The area of the metal layer for bonding formed on the glass substrate is smaller than the area of the region of the glass substrate facing the semiconductor substrate by a distance corresponding to the thickness of the bonded metal layer.

  In the present invention, similarly to the invention of claim 1, the temperature for bonding can be lowered to around 200 ° C. by selecting the material of the metal layer formed on each of the semiconductor substrate and the glass substrate. Further, the area of the metal layer for bonding formed on the glass substrate is made smaller than the area of the region of the glass substrate facing the semiconductor substrate by a distance corresponding to the thickness of the bonding metal layer. A region where the metal layer is not formed can exist in a region of the glass substrate facing the semiconductor substrate at a distance corresponding to the thickness of the metal layer. Since this region (of the glass substrate on which the metal layer is not formed) is a semiconductor substrate or a portion where the metal layer on the semiconductor substrate and the glass substrate are directly closest to each other, the semiconductor substrate and the metal on the semiconductor substrate As a result, it becomes possible to bond the metal layers that are in contact with each other with an applied voltage that is used for ordinary anodic bonding. .

  The invention of claim 3 is the invention of claim 1 or claim 2, wherein the shape of the metal layer for bonding formed on the glass substrate is a lattice shape, a honeycomb shape, a ring shape, a stripe shape, a polka dot Shape, island shape, or a combination thereof.

  The shape of the metal layer for bonding formed on the glass substrate is either a lattice shape, a honeycomb shape, a ring shape, a stripe shape, a polka dot shape, an island shape, or a combination thereof, An electrostatic attractive force generated between the semiconductor layer or the semiconductor substrate can be applied uniformly to the bonding surface.

  The invention of claim 4 is the invention of claim 1 or claim 2, wherein the glass substrate and the semiconductor layer or the metal layer formed on each of the glass substrate and the semiconductor substrate are bonded to each other. The metal layer is gold, and the other metal layer is gold, tin, or indium.

Such a combination enables metal bonding at around 200 ° C.
The invention of claim 5 is a method of manufacturing a semiconductor sensor comprising a glass substrate and a substrate having a semiconductor layer on at least one surface and a movable portion formed on the semiconductor layer. And forming a metal layer on the semiconductor layer in a region corresponding to the bonding portion of the semiconductor layer, and facing the semiconductor layer at a distance corresponding to the thickness of the bonding metal layer after bonding. A step of forming a metal layer on the glass substrate in which the metal layer for bonding having an area smaller than the area of the region is formed in the region of the glass substrate; In a state where the metal layer on the glass substrate is in contact, a DC voltage is applied between the semiconductor layer and the glass substrate so that the semiconductor layer is at a positive potential. Generate attractive force on the semiconductor layer Having a bonding step of bonding the metal layer of the genus layer and the glass substrate.

  By selecting the material of the metal layer formed on each of the semiconductor layer and the glass substrate, the bonding temperature can be lowered to around 200 ° C. Further, for the bonding, the area of the metal layer for bonding formed on the glass substrate is made smaller than the area of the glass substrate region facing the semiconductor layer by a distance corresponding to the thickness of the bonding metal layer after bonding. In a state where the metal layer on the semiconductor layer and the metal layer on the glass substrate are in contact with each other, in a region of the glass substrate facing the semiconductor layer at a distance corresponding to the sum of the thicknesses of both metal layers, There may be a region where no metal layer is formed. Since this region (of the glass substrate on which the metal layer is not formed) is the portion where the semiconductor layer or the metal layer on the semiconductor layer and the glass substrate are directly closest to each other, the metal on the semiconductor layer and the semiconductor layer As a result, it becomes possible to bond the metal layers that are in contact with each other with an applied voltage that is used for ordinary anodic bonding. .

  The invention according to claim 6 is a method of manufacturing a semiconductor sensor in which a semiconductor substrate on which a movable part is formed and a glass substrate are bonded to each other in a region corresponding to the bonding portion of the semiconductor substrate. Forming a metal layer on the semiconductor substrate for forming a metal layer, and an area smaller than the area of the glass substrate facing the semiconductor substrate at a distance corresponding to the thickness of the bonded metal layer after bonding. In a state where the metal layer on the glass substrate for forming the metal layer for bonding, and the metal layer on the semiconductor substrate and the metal layer on the glass substrate are in contact with each other by aligning both substrates, A direct current voltage is applied between the semiconductor substrate and the glass substrate so that the semiconductor substrate is at a positive potential, and an electrostatic attractive force is generated between the semiconductor substrate and the glass substrate. Metal layer on the substrate Having a joining step of engaged.

  By selecting the material of the metal layer formed on each of the semiconductor substrate and the glass substrate, the bonding temperature can be lowered to around 200 ° C. In addition, for the bonding, the area of the metal layer for bonding formed on the glass substrate is made smaller than the area of the glass substrate region facing the semiconductor substrate by a distance corresponding to the thickness of the bonding metal layer after bonding. In a state where the metal layer on the semiconductor substrate and the metal layer on the glass substrate are in contact with each other, in a region of the glass substrate facing the semiconductor substrate at a distance corresponding to the sum of the thicknesses of both metal layers, There may be a region where no metal layer is formed. Since this region (of the glass substrate on which the metal layer is not formed) is a semiconductor substrate or a portion where the metal layer on the semiconductor substrate and the glass substrate are directly closest to each other, the semiconductor substrate and the metal on the semiconductor substrate As a result, it becomes possible to bond the metal layers that are in contact with each other with an applied voltage that is used for ordinary anodic bonding. .

  In the first aspect of the invention, the temperature for bonding can be lowered to around 200 ° C. by selecting the material of the metal layer formed on each of the semiconductor layer and the glass substrate. Further, the area of the metal layer for bonding formed on the glass substrate is made smaller than the area of the glass substrate region facing the semiconductor layer by a distance corresponding to the thickness of the bonding metal layer. A region where the metal layer is not formed can exist in a region of the glass substrate facing the semiconductor layer at a distance corresponding to the thickness of the metal layer. Since this region (of the glass substrate on which the metal layer is not formed) is the portion where the semiconductor layer and the metal layer on the semiconductor layer and the glass substrate directly face each other closest to each other, the semiconductor layer or the metal on the semiconductor layer As a result, it becomes possible to bond the metal layers that are in contact with each other with an applied voltage that is used for ordinary anodic bonding. .

Therefore, according to the present invention, it is possible to provide a semiconductor sensor which is low in cost and can obtain stable characteristics at a low substrate bonding temperature.
In the invention of claim 2, as in the invention of claim 1, the temperature for bonding is lowered to around 200 ° C. by selecting the material of the metal layer formed on each of the semiconductor substrate and the glass substrate. Can do. Further, the area of the metal layer for bonding formed on the glass substrate is made smaller than the area of the region of the glass substrate facing the semiconductor substrate by a distance corresponding to the thickness of the bonding metal layer. A region where the metal layer is not formed can exist in a region of the glass substrate facing the semiconductor substrate at a distance corresponding to the thickness of the metal layer. Since this region (of the glass substrate on which the metal layer is not formed) is a semiconductor substrate or a portion where the metal layer on the semiconductor substrate and the glass substrate are directly closest to each other, the semiconductor substrate and the metal on the semiconductor substrate As a result, it becomes possible to bond the metal layers that are in contact with each other with an applied voltage that is used for ordinary anodic bonding. .

Therefore, according to the present invention, it is possible to provide a semiconductor sensor which is low in cost and can obtain stable characteristics at a low substrate bonding temperature.
In the invention of claim 3, the shape of the metal layer for bonding formed on the glass substrate is any one of a lattice shape, a honeycomb shape, a ring shape, a stripe shape, a polka dot shape, an island shape, or a combination thereof. Therefore, the electrostatic attractive force generated between the glass substrate and the semiconductor layer or the semiconductor substrate can be evenly applied to the bonding surface.

Therefore, according to the present invention, since the electrostatic attractive force necessary for joining can be reduced, the applied voltage necessary for joining can be reduced, and the workability of the joining process is improved.
In the invention of claim 4, the material of the metal layer formed on each of the glass substrate and the semiconductor layer or the glass substrate and the semiconductor substrate to be bonded is gold, one metal layer is gold, and the other metal layer is gold. As described in the examples, it is possible to perform metal bonding at around 200 ° C., and according to the present invention, it is possible to obtain stable characteristics with low cost and low substrate bonding temperature. It is possible to reliably provide a semiconductor sensor.

  In the invention of claim 5, the temperature for bonding can be lowered to around 200 ° C. by selecting the material of the metal layer formed on each of the semiconductor layer and the glass substrate. Further, for the bonding, the area of the metal layer for bonding formed on the glass substrate is made smaller than the area of the glass substrate region facing the semiconductor layer by a distance corresponding to the thickness of the bonding metal layer after bonding. In a state where the metal layer on the semiconductor layer and the metal layer on the glass substrate are in contact with each other, in a region of the glass substrate facing the semiconductor layer at a distance corresponding to the sum of the thicknesses of both metal layers, There may be a region where no metal layer is formed. Since this region (of the glass substrate on which the metal layer is not formed) is the portion where the semiconductor layer or the metal layer on the semiconductor layer and the glass substrate are directly closest to each other, the metal on the semiconductor layer and the semiconductor layer As a result, it becomes possible to bond the metal layers that are in contact with each other with an applied voltage that is used for ordinary anodic bonding. .

Therefore, according to the present invention, it is possible to provide a semiconductor sensor which is low in cost and can obtain stable characteristics at a low substrate bonding temperature.
In the invention of claim 6, the temperature for bonding can be lowered to around 200 ° C. by selecting the material of the metal layer formed on each of the semiconductor substrate and the glass substrate. In addition, for the bonding, the area of the metal layer for bonding formed on the glass substrate is made smaller than the area of the glass substrate region facing the semiconductor substrate by a distance corresponding to the thickness of the bonding metal layer after bonding. In a state where the metal layer on the semiconductor substrate and the metal layer on the glass substrate are in contact with each other, in a region of the glass substrate facing the semiconductor substrate at a distance corresponding to the sum of the thicknesses of both metal layers, There may be a region where no metal layer is formed. Since this region (of the glass substrate on which the metal layer is not formed) is a semiconductor substrate or a portion where the metal layer on the semiconductor substrate and the glass substrate are directly closest to each other, the semiconductor substrate and the metal on the semiconductor substrate As a result, it becomes possible to bond the metal layers that are in contact with each other with an applied voltage that is used for ordinary anodic bonding. .

  Therefore, according to this invention, similarly to the invention of claim 5, it is possible to provide a semiconductor sensor which is low in cost and can obtain stable characteristics at a low substrate bonding temperature.

Sectional drawing which shows the structure of the Example of the semiconductor sensor by this invention, and shows the manufacturing method The structure of the principal part of an Example is shown, (a) is sectional drawing of the through-hole vicinity, (b) is sectional drawing of an outer peripheral part. The block diagram which shows the manufacturing process of the semiconductor sensor by this invention Block diagram showing the manufacturing process of a conventional semiconductor sensor using metal bonding Conceptual sectional view showing the structure of an example of a conventional semiconductor sensor and showing its manufacturing method FIG. 5 shows the structure of the main part of the conventional example shown in FIG. 5, where (a) is a cross-sectional view in the vicinity of a through hole, and (b) is a cross-sectional view of an outer peripheral portion Sectional drawing which shows the structure of the other example of the semiconductor sensor by a prior art, and shows the manufacturing method Sectional view showing the structure in the vicinity of the through hole immediately after anodic bonding in the conventional example shown in FIG. Sectional drawing which shows the structure of the state which formed the through-hole metal layer in the through-hole of the prior art example shown in FIG.

  As described in the section of “Means for Solving the Problems”, the feature of the present invention is that a bonding material for metal bonding and generation of pressing force for anodic bonding are used to bond a glass substrate and a semiconductor layer or a semiconductor substrate. In order to generate the pressing force necessary for bonding with the applied voltage used for normal anodic bonding, the area of the metal layer for bonding formed on the glass substrate is the bonding metal layer. The area corresponding to the thickness of the semiconductor layer or the area of the glass substrate facing the semiconductor substrate is made smaller than the area of the glass substrate, and a region for generating the electrostatic attraction necessary exists around the metal layer to be joined. That is.

  In the following, the present invention will be described in more detail with reference to examples.

  FIG. 1 is a conceptual cross-sectional view showing a structure of an embodiment of a semiconductor sensor according to the present invention and a manufacturing method thereof, FIG. 2 shows a structure of a main part of the embodiment, and FIG. Sectional drawing, (b) is a sectional view of the outer periphery, and FIG. 3 is a block diagram showing the manufacturing process of the semiconductor sensor according to the present invention.

  This embodiment is structurally the same as the conventional example shown in FIGS. The difference is that the shape of the metal layer 23 formed on the glass substrate 2 has been replaced with a grid-like pattern in which a solid pattern is combined with a narrow band and applied to the bonding surface. That is, the pressure by the pressurizing means is replaced by electrostatic attractive force between the substrates by the DC voltage applied to the semiconductor layer 13 and the glass substrate 2 and the semiconductor substrate 11 and the glass substrate 3, respectively.

  In this embodiment, an SOI substrate 1 in which a movable part 131 and an electrode pattern 132 are formed on a semiconductor layer 13 which is a silicon active layer, and two glass substrates 2 and 3 which are arranged and integrated on both sides thereof are integrated. It consists of and. At least the glass substrate 2 is provided with an electrode (not shown) that faces the movable portion 131.

  A movable part 131 is formed in the central part of the semiconductor layer 13 of the SOI substrate 1, and an electrode pattern 132 is formed outside thereof. The movable part 131 includes an electrode pattern 132, a metal layer 14 formed on a part of the surface of the electrode pattern 132, a metal layer 23a formed on the surface of the glass substrate 2, and an inner surface of the through hole 21 of the glass substrate 2. It is electrically connected to the outside through the formed through hole metal layer 22.

  The metal layer 14 and the metal layer 23a are joined to form the joint portion 4a, so that the electrical connection is ensured and the through hole 21 is hermetically sealed at the same time. Therefore, the pattern of the metal layer 23a is formed in a shape surrounding the through hole 21, and in this embodiment, as described above, is a lattice shape and is connected to the through hole metal layer 22.

  Similarly, the electrode on the glass substrate side (not shown) is also connected to the outside through a through hole, and in order to make the inside airtight, the same bonding as described above is also adopted in this through hole portion.

  Further, in order to ensure the airtightness of the entire sensor, a ring-shaped metal layer 15 formed on the semiconductor layer 13 and a quadruple ring-shaped metal layer 24a formed on the glass substrate are provided on the outer periphery of the sensor. Are joined to form a joint 4a (see FIG. 2B).

  As shown in FIG. 3, the bonding process between the metal layer 14 on the semiconductor layer 13 and the metal layer 23a on the glass substrate 2 forms the respective metal layers at predetermined positions on the respective substrates. After the layer formation step and the metal layer formation step on the glass substrate are aligned and overlapped with each other, the glass substrate is negatively placed between the semiconductor layer and the glass substrate while heating to a predetermined temperature. It is composed of a metal layer joining step by electrostatic attraction, in which a direct current voltage is applied so as to be at a potential, and both metal layers in contact are joined by a pressing force by electrostatic attraction.

  In this embodiment, gold is used as the material of the metal layer 14 and the metal layer 15, the thickness is 0.5 μm, gold is also used as the material of the metal layer 23a and the metal layer 24a, and the thickness is 0.3 μm. The metal layer 14 and the metal layer 23a and the metal layer 15 and the metal layer 24a could be joined in a good joined state by setting the heating temperature at the time of joining to 250 ° C. and the applied voltage for joining to 300V.

  In this example, the area where the metal layer was formed on the glass substrate was about 30% of the total area that could be joined. Here, the “total area that can be bonded” is the area of the portion to be bonded in the case of anodic bonding, and is the area of the glass substrate facing the semiconductor substrate at a distance corresponding to the thickness of the bonding metal layer. That is.

  In this example, gold was used as the material for both metal layers, but if one of the materials is gold and the other is tin, the melting point of tin is 232 ° C, so the heating temperature is further 20 ° C. If the tin is changed to indium, the melting point of indium is 156 ° C., so that the temperature can be further lowered.

  In addition, the value of the applied voltage required for bonding is determined by the thickness of the metal layers 23a and 24a formed on the glass substrate 2, the thickness of the metal layers 14 and 15 formed on the semiconductor layer 13, and the metal layer of the glass substrate 2. It is determined by the ratio of the area of the metal layer 23a and the area of the metal layer 14 to the pattern 23a and the total area that can be joined. The thickness of the metal layer corresponds to the gap of the portion that generates electrostatic attraction, and the pattern of the metal layer is related to the area of the portion that generates electrostatic attraction. Therefore, the thickness of the metal layer, in particular, the thickness of the metal layers 23a and 24 is reduced within a range where there is no practical problem, and the ratio of the metal layers 23a and 24a is reduced within a range where the necessary rigidity as a sensor can be secured By increasing the ratio of the metal layers 14 and 15, the applied voltage can be lowered.

  Further, in this embodiment, the metal layer 23a is a lattice pattern and the metal layer 24a is a ring pattern. However, in consideration of the necessity of the airtightness of the sensor, etc. It is also effective to adopt a striped pattern that is a combination of a striated pattern, a light pattern, a honeycomb pattern that can be used in the same manner as a lattice pattern, and it is also effective to use a combination of these patterns.

  Although this embodiment is a semiconductor sensor using an SOI substrate, even a sensor in which the SOI substrate is replaced with a semiconductor substrate can perform the same bonding as this embodiment.

1 SOI substrate
11 Semiconductor substrate 12 Insulator layer
13 Semiconductor layer
131 Movable part 132 Electrode pattern
14, 15 (on semiconductor layer) metal layer 2, 3 glass substrate
21 Through hole 22, 22a Through hole metal layer
23, 23a (on glass substrate) Drawer metal layer
24, 24a (on glass substrate) Metal layer for sealing 4, 4a Metal joint 5 Heater

Claims (6)

A semiconductor sensor comprising a glass substrate and a substrate having a semiconductor layer on at least one surface and having a movable part formed on the semiconductor layer,
The two substrates are joined by metal layers formed on the semiconductor layer and the glass substrate,
And the area of the metal layer for bonding formed on the glass substrate is smaller than the area of the region of the glass substrate facing the semiconductor layer at a distance corresponding to the thickness of the bonded metal layer,
A semiconductor sensor characterized by the above. A semiconductor sensor configured by bonding a semiconductor substrate and a glass substrate on which a movable part is formed,
The two substrates are joined by a metal layer formed on each,
And the area of the metal layer for bonding formed on the glass substrate is smaller than the area of the region of the glass substrate facing the semiconductor substrate at a distance corresponding to the thickness of the bonded metal layer,
A semiconductor sensor characterized by the above. The shape of the metal layer for bonding formed on the glass substrate is a lattice shape, a honeycomb shape, a ring shape, a stripe shape, a polka dot shape, an island shape, or a combination thereof,
The semiconductor sensor according to claim 1 or claim 2, wherein The material of the glass substrate and the semiconductor layer to be bonded or the metal layer formed on each of the glass substrate and the semiconductor substrate, one metal layer is gold, and the other metal layer is either gold, tin, or indium Is,
The semiconductor sensor according to claim 1 or claim 2, wherein A method of manufacturing a semiconductor sensor comprising a substrate having a semiconductor layer on at least one surface and having a movable part formed on the semiconductor layer and a glass substrate joined together,
A metal layer on semiconductor layer forming step of forming a metal layer for bonding in a region corresponding to a bonding portion of the semiconductor layer;
Formation of a metal layer on a glass substrate that forms a metal layer for bonding in an area smaller than the area of the glass substrate facing the semiconductor layer at a distance corresponding to the thickness of the bonding metal layer after bonding. Process,
With both substrates aligned and in contact with the metal layer on the semiconductor layer and the metal layer on the glass substrate, direct current is applied so that the semiconductor layer is at a positive potential between the semiconductor layer and the glass substrate. A bonding step of applying a voltage to generate an electrostatic attractive force between the semiconductor layer and the glass substrate to bond the metal layer on the semiconductor layer and the metal layer on the glass substrate;
Having
A method for manufacturing a semiconductor sensor. A method of manufacturing a semiconductor sensor comprising a glass substrate and a semiconductor substrate on which a movable part is formed,
A metal layer forming step on the semiconductor substrate for forming a metal layer for bonding in a region corresponding to the bonding portion of the semiconductor substrate;
Formation of a metal layer on a glass substrate that forms a metal layer for bonding in an area smaller than the area of the glass substrate facing the semiconductor substrate at a distance corresponding to the thickness of the bonding metal layer after bonding. Process,
With both substrates aligned and in contact with the metal layer on the semiconductor substrate and the metal layer on the glass substrate, a direct current is applied so that the semiconductor substrate is at a positive potential between the semiconductor substrate and the glass substrate. Applying a voltage, generating an electrostatic attractive force between the semiconductor substrate and the glass substrate, and joining the metal layer on the semiconductor substrate and the metal layer on the glass substrate;
Having
A method for manufacturing a semiconductor sensor.